Recruitment Characteristics Of Juvenile Striped Bass (Morone Saxatilis) Across Recovery Periods, Year Classes, And Subestuaries Of The Chesapeake Bay
Master of Science (M.Sc.)
Virginia Institute of Marine Science
Mary C Fabrizio
Mark J Brush
Robert J Latour
David H Secor
The Atlantic coast striped bass fisheries collapsed in the late 1970's due to recruitment overfishing and poor habitat quality. Recovery of the fisheries in 1995 resulted from protection of mature females, favorable environmental conditions, and several years of strong recruitment. Today, the striped bass stock is overfished. The purpose of this study was to examine recruitment characteristics of juvenile striped bass during the pre- and post-recovery periods through (1) a comparison of mortality and hatch-date distribution between periods, and (2) to examine growth metrics of individuals from the post-recovery year classes. Lengths and otolith-derived daily ages from juvenile striped bass representing three year classes (2011, 2016, and 2017) from the James and Rappahannock subestuaries of the Chesapeake Bay were used to develop subestuary-specific age-length keys. Daily ages of juvenile striped bass from 32 year classes (1986 to 2017) spanning the pre- and post-recovery periods were projected from the age-length keys. Together with count data, the projected daily ages were used to estimate instantaneous daily mortality rates (Z, day-1) for each year class. Although daily Z estimates were relatively constant among the 32 year classes, mean hatch dates shifted earlier today (1996 to 2017) than prior to 1995. Within the post-recovery year classes, daily growth in length and weight was examined along with body condition (Fulton's K). All growth metrics varied by year class and subestuary, but daily growth rates and body condition were inversely related. The results of this study indicate that recruitment dynamics of juvenile striped bass in the Virginia portion of the Chesapeake Bay have changed over time, and within the post-recovery year classes, those changes varied among fish from the James and Rappahannock subestuaries.
© The Author
Phillips, Olivia M., "Recruitment Characteristics Of Juvenile Striped Bass (Morone Saxatilis) Across Recovery Periods, Year Classes, And Subestuaries Of The Chesapeake Bay" (2020). Dissertations, Theses, and Masters Projects. William & Mary. Paper 1593091767.